Gyrating sifter drive



Dec, 3, 1935. J. F. PERKINSON GXRATING SIFTER DRIVE Filed Aug. 25, 1954 do 1 W Ina n? IHH 7 3,1 gmnnl o'o Patented Dec. 3, 1935 UNITED STATES GYRATING SIFTER DRIVE James Frank Perkinson, Danville, Va.

Application August 25, 1934, Serial No. 741,470

8 Claims.

The invention relates to sifting devices, such for instance as flour sifters in which the sifter box is flexibly suspended by appropriate means and given a lateral gyratory movement by means of a mechanism driven by a belt running on a pulley below the sifter box.

The principal object of the invention, generally stated, is to provide a novel gravity means which is centrifugally operated in accordance with the speed of rotation of the drive pulley and which will act to impart the desired gyratory movement to the sifter.

Another object of the invention is to provide an apparatus of this character in which the construction is such that even when the drive mechanism is at rest the center of gravity of the gymtion producing Weight will be off-center with respect to the axis of the drive pulley and its associated parts, thereby rendering it impossible for the parts to lock or stick in a centered or coaxial relation, a condition which would result in failure of the gyration producing means to operate.

Another object, and an important one, is to provide a gravity device for the purpose specified in which the weight may be varied to take care of different conditions or circumstances so as to insure an action most conductive to efiiciency.

Still another object is to provide an apparatus of this character which does not involve any changes whatsoever in the usual construction and mounting of the sifter box and which is, moreover, located entirely below the sifter so as to be out of the way and easily accessible for lubricating or adjusting purposes.

A still further object of the invention is to provide a drive of this character in which the bearing surfaces and elements are submerged in oil or other lubricant so that there will be the maximum ease of movement and freedom from friction.

An additional object is to provide a drive mechanism of this character which will be simple and inexpensive to manufacture, easy to install and adjust, positive in action, eflicient and durable in service, and a general improvement in the art.

To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of the device, the

normal or at-rest position of the weighted arm being shown by full lines and its outflung position by dot and dash lines,

Figure 2 is a fragmentary elevation on a larger scale with the weighted arm shown in longitudi- 5 ml section and in normal or at-rest position,

Figure 3 is a view principally in longitudinal section through the upper or bearing portion of the device,

Figure 4 is a detail cross section taken on the 10 line 44 of Figure 3.

Referring more particularly to the drawing the letter A designates a sifter box of the usual construction suspended by means of the flexible rods or reeds B in the customary manner. The 15 ordinary chutes provided for conducting material to and from the sifter box are not shown as they form no part of the present invention. Secured upon the underside of the sifter box is a casting or bracket C from which depends a 20 shaft D which might conceivably be integral therewith or which may be rigidly secured thereto for instance as shown in Figure 1. This shaft is of course stationary and constitutes a support for the rotatable mechanism to be described. In 25 devices of this general class it is customary to provide a' pulley E for driving whatever gyration producing means is employed and such a pulley is driven by means of a belt F trained about it and about a guide pulley G carried by 30 the sifter box and driven by any suitable means.

In carrying out my invention I provide a hollow or tubular hub l0 which is rotatable with respect to the shaft D. The lower end of the bore of this hub is closed by a cap or plate 35 H which serves to enclose the depending shaft. Near the upper end of the hub there is provided a ball bearing structure 12 arranged to receive radial thrusts and at the lower end there is provided another ball bearing structure I3 con- 40 structed toreceive not only radial thrusts but also to support the hub upon the shaft. The outer raceways of the ball bearing structures l2 and l3 seat upon ledges l4 and 15 formed in the bore of the hub, and the inner raceway of the lower 45 ball bearing structure l3 seats .against a shoulder [6 at the lower portion of the shaft D. Assembly is completed by means of a disk or plate I! engaged upon the reduced lower end of the shaft and secured in place by a nut I8 threaded 50 onto the end of the shaft. Seating upon the upper ball bearing structure I2 is a disk l9 above which is packing 20 held in place by a packing gland 2| secured by cap screws 22. The space within the hub is filled with suitable lubricant s0 that the ball bearing structures will be submerged therein and will be constantly effectually lubricated. The packing 2E] and gland 2| prevent any leakage of the lubricant upwardly along the shaft.

The upper portion of the hub ll] carries the pulley E which is rigidly secured thereto for rotation therewith, by any suitable means. While the upper portion of the hub is cylindrical the lower portion 23 is preferably rectangular in shape and provided at its sides with stop lugs 24 projecting laterally therefrom for a purpose to be described.

Arranged below the hub member I9 is an arm 25 formed as an elongated metalliomember provided at its upper end with spacedears 26 which straddle the hub member and which are pivoted thereto as by cap screws 21, it being preferable to provide washers 28 beneath the heads of the cap screws. The upper end of the arm 25 is cut back as shown at 29 asufficient distance to clear the bottom plate H and the cap screws holding the same in place. This arm 25 depends from the hub member in a somewhat inclined position as shown in Figure 2 with the edges of the ears 26 engaging against the stops 24 on the lower portion of the hub member, the purpose being to prevent the arm 25 from ever getting into such position that its center of gravity will coincide with the axis of the shaft D and hub member Ill.

It is desirable to provide an adjustment for varying the degree or violence of gyration and this is easily accomplished by providing any desired number of weights 36 of any preferred size I located at the lower end of the arm 25 and threaded onto a bolt or threaded rod 3! equipped with a nut 32 for the purpose of securing the weights against relative movement with respect to the arm. I

Assuming that the device has been constructed and arranged as described and as illustrated in the drawing, it will be seen that normally or initially, that is to say when the device is at rest, the arm 25 with its weights 30 hangs down in a slightly inclined positionlas shown by full lines in Figure 1 and also as shown in Figure 2. When the belt F is driven the pulley E is of course rotated, carrying with it the hub member H] and the arm 25 suspended therefrom. The weighted arm 25 then swings outwardly and upwardly under the influence of centrifugal force, as indicated by dot and dash lines in Figure l, the extent of upward movement being dependent upon the speed of rotation. Clearly, the unbalanced effect caused by this arm projecting laterally beyond the axis of the rotating pulley and hub member will cause a gyratory action to be imparted to the sifter box, thereby operating it in the desired manner to accomplish the customary results. As mentioned above, by'providing more or larger weights 39 regulation of the upward and outward swinging movement of the arm 25 with respect to the speed of rotation may be effected.

From the foregoing description and a study of the drawing it will be apparent that I have thus provided a very simply constructed and consequently inexpensive-shaker mechanism or gyratory drive which is not limited for use in association with flour sifters but whichcan be employed in numerous arts for various purposes, in fact wherever it isdesired to have a gyratory action. Ample provision has been made to insure thorough lubrication as itis a simplematter to provide any ordinary or preferred type of lubricant inlet for the hub member enabling lubricant to be forced into the interior thereof. Moreover, adjustment as to the throw or time of throw of the arms with respect to the speed has been taken care of. It will be noted that the entire mechanism is located below the sifter box in an out of the way position and so as to be accessible in case of any necessity for repairs or adjustments. It is thought from the foregoing that the construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.

While I have shown and described the preferred embodiment of the invention, it should be 3 understood that the disclosure is merely an exemplification of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or thescope of the claims hereunto appended.

Having thus described the invention, I claim:

1. A gyrating drive mechanism for a sifter flexibly suspended and having a depending shaft, comprising a hub member rotatably mounted upon and enclosing the lower end of said shaft and equipped with means for rotating the same, a weighted arm pivotally suspended from said hub member, and means on the hub member cooperating with the arm for maintaining said arm normally and initially in an inclined position with respect to the axis of the shaft and hub member.

2. A gyrating drive mechanism for a sifter flexibly suspended and having a depending shaft, comprising a hub member rotatably mounted upon said shaft and equipped with means for rotating the same, a weighted arm pivotally suspended from said hub member, means for maintaining said arm normally and initially in an inclined position with respect to the axis of the shaft and. hub member, a plurality of selectively usable weights arranged in axial relation to said arm for varying the weight and length thereof, and means for securing the weights to the arm.

3. A gyrating drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a tubular hub member surrounding the shaft in coaxial relation thereto and extending below the lower end thereof, bearing means within the hub member coacting with said shaft and supporting the hub member from the shaft,

means closing the ends of said hub member and defining a chamber for containing lubricant, a drive pulley secured to said hub member, a depending arm having its upper end provided with spaced ears straddling the hub'member and pivoted thereto, and means on the hub member 00- acting with said ears for maintaining the arm normally or initially in an inclined position with respect to the axis of theshaft and hub member.

4. A gyratory drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a hub member equipped internally with bearing means cooperating with said shaft and suspended from the shaft and projecting therebelow, a rotary drive member carried by the upper end of the hub, an arm located beneath the hub member and having its upper end formed with spaced ears straddling the lower portion of the hub member, pivot elements passing through said ears and into the hub member and enabling said arm toswing upwardly and outwardly under the influence of centrifugal force when the hub member is rotated, and stop lugs on the opposite sides of the hub member engageable by said ears for holding the arm initially or normally in a downwardly inclined position with its center of gravity eccentrically disposed with respect to the longitudinal axis of the shaft and hub membar.

5. A gyratory drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a hub member equipped internally with bearing means cooperating with said shaft and suspended from the shaft and projecting there- .below, a rotary drive member carried by the upper end of the hub, an arm located beneath the hub member and having its upper end formed with spaced ears straddling the lower portion of the hub member, pivot elements passing through said ears and into the hub member and enabling said arm to swing upwardly and outwardly under the influence of centrifugal force when the hub member is rotated, stop lugs on the opposite sides of the hub member engageable by said ears for holding the arm initially or normally in a downwardly inclined position with its center of gravity eccentrically disposed with respect to the longitudinal axis of the shaft and hub member, a threaded rod carried by the lower end of said arm, Weights removably engaged upon said rod, and a nut screwed onto the rod for securing the weights against relative movement with respect to the arm.

6. A gyrating drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a tubular hub member surrounding the shaft in coaxial relation thereto and extending below the lower end thereof, bearing means within the hub member coacting with said shaft and supporting the hub member from the shaft, means closing the ends of said hub member and defining a chamber for containing lubricant, a drive pulley carried by said hub member, and a weighted depending arm having its upper end 5 pivotally connected with the hub member.

7. A gyrating drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a tubular hub member surrounding the shaft in coaxial relation thereto and extending between the lower end thereof, said hub member having its bore provided with upper and lower shoulders, bearing means disposed against said respective shoulders, a retaining element on the lower end of said shaft beneath the lower bearing means for suspending the hub from the shaft, means closing the ends of the bore in the hub member and defining a chamber for containing lubricant, a drive element carried by said hub member, and a weighted depending arm having its upper end pivotally engaged upon the hub member.

8. A gyrating drive mechanism for a flexibly suspended sifter having a depending shaft, comprising a hub member rotatably mounted upon said shaft and equipped with means for rotating the same, a weighted arm having a forked upper end straddling and pivotally suspended from said hub member and having its lower end extending below the shaft, and stop lugs on the opposite sides of the hub member engageable by the edges of the forked upper end of the arm for holding the arm initially or normally in a downwardly inclined position with its center of gravity eccentrioally disposed with respect to the longitudinal axis of the shaft and hub member.

JAMES FRANK PERKINSON. 

